STOP AND START STOP AND START SYSTEM Failure to Restart from IG-ON Engine Stall
DESCRIPTION
This is the troubleshooting procedure for situations where the engine does not restart when attempting to restart it after a failed engine start occurred under stop and start system control.
CAUTION / NOTICE / HINT
PRECAUTIONS WHEN THE ENGINE STOP AND START ECU AND THE STARTER ASSEMBLY ARE REPLACED
- NOTICE:
- ·
When the engine stop and start ECU is replaced, it is necessary to read the number of starter operations before replacement and store this number in the new engine stop and start ECU after replacement, and to perform external backup boost converter (eco run vehicle converter assembly) existence learning. Moreover, initialization/learning of the air conditioning information and initialization/learning of the deceleration sensor zero point are also required.
·When the starter assembly is replaced, the number of starter operations stored in the engine stop and start ECU must be reset.
·When the starter assembly is replaced, "ST relay" must be also replaced.
·Inspect the fuses for circuits related to this system before performing the following procedure.
PRECAUTIONS FOR FOUR-WHEEL TOWING
Do not tow the vehicle with all 4 wheels on the ground.
- NOTICE:
- ·
Towing the vehicle with all 4 wheels on the ground may have a detrimental effect on the stop and start system, and could lead to damage.
- HINT:
-
If it is absolutely necessary to tow the vehicle with all 4 wheels on the ground, before towing first turn the ignition switch off. Then, turn the ignition switch to ON without starting the engine, and tow the vehicle.
PRECAUTIONS WHEN REPLACING ECM
- NOTICE:
-
When the ECM is replaced on a vehicle with a non-specified auxiliary battery, it is necessary to perform auxiliary battery type switching.
PROCEDURE
Using the GTS, check Vehicle Control History (RoB).
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
- Result:
Result Proceed to Vehicle control history (RoB) [X0874: Stop & Start Restart Failure (Engine Restart after Engine Stall)] is output A Vehicle control history (RoB) [X0874: Stop & Start Restart Failure (Engine Restart after Engine Stall)] is not output B
A
B
DIAGNOSTIC TROUBLE CODE CHART:
Consult with the customer to determine if they performed operations that could result in an engine stall.
- HINT:
-
(ex.) Heavy load, frequent shifts, etc.
- Result:
Result Proceed to Driver operations that could cause engine stall were performed A None of the above conditions are met B
A
B
Using the GTS, check Vehicle Control History (RoB).
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
Select the vehicle control history (RoB) item [X0874: Stop&Start Restart Failure (Engine Restart after Engine Stall)] to display the data from the time of control.
Check the output data.
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
- Result:
Result Proceed to All recorded sections Starter Motor = OFF, and all recorded sections Engine Speed = 0 rpm
- HINT:
-
It is possible that the starter drive command is not being sent from the engine stop and start ECU.
A Starter Motor = ON for any sections, and all recorded sections Engine Speed = 0 rpm
- HINT:
-
It is possible that the drive command is being sent from the engine stop and start ECU but the starter itself is not moving.
B Engine Speed > 0 rpm for any sections
- HINT:
-
It is possible that cranking was achieved but the engine stopped.
C
A
- HINT:
-
It is possible that there is a malfunction of the starter drive circuit inside the stop and start ECU.
B
C
Using the GTS, check Vehicle Control History (RoB).
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
Select a vehicle control history (RoB) item to display the data from the time of control.
Check the output data.
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
- Result:
Result Proceed to Cranking Time is 1.5 seconds or more
- HINT:
-
It is possible that there is an external malfunction outside of the stop and start ECU (drive circuit).
A Cranking Time is less than 1.5 seconds
- HINT:
-
It is possible that there is a malfunction in the stop and start ECU (drive circuit).
B
A
B
Disconnect the A169 engine stop and start ECU connector.
Turn the ignition switch to ON.
Turn off any electrical loads.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition A169-1 (+B) - Body ground Ignition switch ON 11 V or higher
- Result:
Proceed to OK NG
OK
NG
Using the GTS, check Vehicle Control History (RoB).
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
Select a vehicle control history (RoB) item to display the data from the time of control.
Check the output data.
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
·Depending on RoB detection timing, the minimum voltage from the previous startup will be stored for the Minimum Voltage (Cranking) and the Minimum Voltage (Starter Solenoid Engagement). For the auxiliary battery condition at the start of the current driving cycle, see Battery Voltage.
·When the value is 20 V, the value is being calculated.
- Result:
Result Proceed to Battery Voltage is 8.92 V or more A Battery Voltage is less than 8.92 V B
A
B
Measure the voltage of the auxiliary battery.
- Standard Voltage:
11 to 14 V
- Result:
Proceed to OK NG
OK
NG
Using the GTS, check Vehicle Control History (RoB).
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
Select a vehicle control history (RoB) item to display the "Cranking Time" and "Starter OFF Permission History (ECM)" data from the time of control.
Check the output data.
- Result:
Result Proceed to "Cranking Time" is less than 1.5 seconds "Starter OFF Permission History (ECM)" is ON
- HINT:
-
It is possible that the ECM made a judgment of complete combustion and the ECM then stopped the starter.
A "Starter OFF Permission History (ECM)" is OFF
- HINT:
-
It is possible that the engine stop and start ECU made a judgment of complete combustion and the engine stop and start ECU then stopped the starter.
B "Cranking Time" is 1.5 seconds or more. - HINT:
-
It is possible that the stop and start ECU did not stop the starter.
C
A
- HINT:
-
Check whether the speed value of the EFI ECU is not a higher value than the original NE.
B
C
In accordance with the display on the GTS, read the Data List.
- Powertrain > Stop and Start > Data List
-
Tester Display Engine Speed Engine Speed (ECM) - 50003 392 502,213
Compare the Data List items displayed on the GTS.
- Result:
Result Proceed to Engine Speed > Engine Speed (ECM) + 100 rpm A None of the above conditions are met B
A
B
In accordance with the display on the GTS, read the Data List.
- Powertrain > Stop and Start > Utility
-
Tester Display Vehicle Control History (RoB) - 50005 392 55
Select a vehicle control history (RoB) item to display the data from the time of control.
Check the data points in the data that was output.
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
- Result:
Result Proceed to For each and all of the data points, "Engine Speed" > "Engine Speed (ECM)" + 100 rpm A None of the above conditions are met B
A
B
| *a | Component with harness connected
(Engine Stop and Start ECU) |
- | - |
Using the GTS, perform Active Test.
- Powertrain > Stop and Start > Active Test
-
Tester Display Starter Motor Drive Magnet Switch(Hood Close) - 50004 392 42019
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition A169-21 (STA) - A169-6 (DGND) Performing Active Test, while cranking. 6 to 14 V
Using an oscilloscope, measure the waveform immediately after starting.
| Item | Content |
|---|---|
| Tester Connection | A169-21 (STA) - A169-6 (DGND) |
| Tool Setting | 10 V/DIV., 200 ms./DIV. |
| Condition | During cranking |
- OK:
Voltage and waveform both normal
- Result:
Proceed to OK NG
OK
NG
| *a | Component with harness connected
(Engine Stop and Start ECU) |
- | - |
Using the GTS, perform Active Test.
- Powertrain > Stop and Start > Active Test
-
Tester Display Starter Motor Drive Magnet Switch(Hood Close) - 50004 392 42019
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition A169-21 (STA) - A169-6 (DGND) Performing Active Test, while cranking. 6 to 14 V
Using an oscilloscope, measure the waveform immediately after starting.
| Item | Content |
|---|---|
| Tester Connection | A169-21 (STA) - A169-6 (DGND) |
| Tool Setting | 10 V/DIV., 200 ms./DIV. |
| Condition | During cranking |
- OK:
Voltage and waveform both normal
- Result:
Proceed to OK NG
OK
NG
Select a vehicle control history (RoB) item to display the data from the time of control.
Check the output data.
- HINT:
- ·
Checking the freeze frame data allows the vehicle conditions at the time of detection to be confirmed.
·As Vehicle Control History (RoB) may be overwritten whenever the trigger conditions are met, make sure to save the Vehicle Control History (RoB) data before performing any inspections.
- Result:
Result Proceed to When Starter Motor is ON, there is even 1 point at which Engine Speed < 300 rpm A None of the above conditions are met B
A
B
Check how long it took the engine to stall after turning the starter off.
- Result:
Result Proceed to After starter turned off, engine immediately stalls.
- HINT:
-
Engine stalls within 2 seconds.
A After starter turned off, engine stalls after a time. B
A
B